One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(12,20)(15,21)(19,24)(22,23)(25,26,31,28)(27,34,37,40)(29,33,30,38)(32,39,35,36)(2,5)(3,7)(9,10,13,16)(11,17,18,14)(12,21,20,15)(19,22,24,23)(9,11)(10,14)(12,19)(13,18)(15,22)(16,17)(20,24)(21,23)(25,27,29,39,31,37,30,36)(26,32,38,40,28,35,33,34)(1,3,4,7)(2,6,5,8)(11,18)(14,17)(19,24)(22,23)(25,28,31,26)(27,35,37,32)(29,33,30,38)(34,36,40,39)(9,12,13,20)(10,15,16,21)(11,19,18,24)(14,22,17,23)(25,29,31,30)(26,33,28,38)(27,36,37,39)(32,40,35,34)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.